Luminaries may be ceiling lights, suspended lights, pendant lights, mast lights or emergency lights. Such an emergency light may be constructed like one of the before-mentioned lights. Such an emergency light may also be an explosion-proof light.
The protective trough or protective cover of such a luminaire may be made of different transparent or translucent materials such as glass, polycarbonate or also of other materials. Moreover, the “protective trough” or “protective cover” may also be constructed like a glass bulb or the like.
Depending on the used illuminant, the associated electric or electronic components are, for instance, a ballast, a starter, a temperature- or also a pressure-measuring device, a fuse or the like.
The corresponding protective trough may be detachably connected to the luminaire housing by a number of screws or the like. Also, it is possible that the protective trough is pivotably mounted on the luminaire housing, for instance by a hinged connection, and can be locked in a corresponding locked position.
In such a prior luminaire the illuminant has a corresponding spectral range for the emitted light. Also, as a rule, no other restrictions with respect to the emission of light are arranged in the protective trough, wherein the emission of light is determined, as a rule, by one or more reflectors arranged inside the luminaire housing, at least with respect to the intensity distribution.
However, light has an influence on the environment, which shows, for instance, in an influence of the natural activities of animals. The reason for this may be that certain animals are more sensitive in certain spectral ranges of the light and may therefore be negatively or also positively influenced by light emitted in this spectral range. This may be the case, for instance, in connection with street lighting, the illumination of pavements or also the illumination of parks or the like.
Furthermore, it can often be noticed in connection with luminaries that they emit light at a relatively large aperture angle. However, in order to illuminate a road, objects etc. only a smaller aperture angle range for such a light is required. The aperture angle exceeding this required aperture angle range is substantially unused and results in a light contamination of the environment, that is, light is emitted to regions in which it is not used or not required.
This also applies to other usages of light, for instance, in rooms in which certain spectral ranges of the emitted light could cause reactions or the like, see for instance biological, chemical or also physical applications.